1. Field of the Invention
This invention relates to arrowheads, and more particularly, to multi-piece arrowhead assemblies known generally as broadheads, which are popular with bow hunters and noted for their long range, deep penetrability, and high lethality.
2. Description of the Prior Art
For thousands of years, archery has played an prominent role in hunting, warfare, and sport. One of the most famous military battles in which archery proved the victors with a decisive advantage occured at Crecy on Aug. 26, 1346. The English under the command of Edward III, occupied the side of a small hill. On the plain below, outnumbering the English four to one, a disorderly host of French knights on horseback and hired Genoese crossbowmen on foot were arrayed under the command of Philip VI. Edward had all his men dismount because they were armed with the new longbow. Though tired after a long day's march and hampered by crossbow strings that had been loosened by a wetting received in a terrific thundershower, the Genoese were ordered to begin the attack. Though they shot fiercely, they were no match for the more rapid shooting of the English longbowmen, whose shafts “fell so thick that it seemed snow.” When the Genoese saw the arrows falling thick among them they threw down their crossbows and ran. King Philip thereupon flew into a rage and ordered his knights to slay the retreating Genoese. As a result, a great number of the mercenaries were killed. Despite being outnumbered by a wide margin, the English army routed the French, killing more than 1,500 of the enemy while losing only 50 men. Flush with victory, the English troops advanced to Calais, which they besieged and eventually captured in 1347.
Archery technology has developed tremendously since its origins thousands of years ago, with more advancements in bow and arrow technology having occured in the past forty years than in the previous thousands. Though no longer used for warfare, archery remains a challenging sport, with the hunter or archer dependent only upon his or her own strength and skill to hit the target precisely or to produce a clean kill of a game animal. The inherent difficulties associated with the sport are incentive enough for continual improvement of the technology, whether the improvements are in the form of more powerful bows, more accurate projectiles, greater stopping power, or greater lethality.
The technology of archery encompasses both launchers and projectiles. A bow (the launcher) is used to propel an arrow (the projectile) towards a target. A conventional arrow has a shaft, a nock that receives the bow string attached to the trailing end of the shaft, and an arrowhead or point attached to the leading end of the arrow shaft, which aids in penetrating the target. An arrowhead generally has a pointed forward end, and an threaded rearward end that attaches to the leading end of the arrow shaft. Arrowheads come in a variety of different sizes and configurations depending on their intended use. For example, there are specifically designed arrowheads for competitive target shooting, shooting fish, hunting birds or small game animals, and for hunting big game animals. Arrowheads used for bowhunting are generally know as broadheads. Broadheads have cutting blades and kill game animals by cutting vital organs such as the lungs and vascular vessels such as arteries, which causes rapid hemorrhaging and/or suffocation. Quick and humane kills are dependent on accurate shot placement, and upon the amount or volume of the animal tissue that is cut. Hunting arrowheads that cut more tissue are more lethal, and therefore are better. The volume of tissue that is cut is determined by the cutting diameter of the arrowhead, the number of blades it contains, and by the distance the arrowhead penetrates into the animal.
The two most common types of arrowheads used for hunting are fixed-blade arrowheads and blade-opening, or mechanical, arrowheads. Blade-opening arrowheads differ from conventional fixed-blade arrowheads in that the cutting blades are folded up against the arrowhead body in a retracted position so as to reduce aerodynamic drag while the arrow is in flight, rotating to an open, more lethal configuration on impact with the game. The blades of fixed-blade arrowheads are permanently held at a full cutting diameter position at all times.
Both blade-opening and fixed-blade arrowheads have a pointed tip end used for penetrating the game animal. The tip of the arrowhead may be separably attachable to the arrowhead body or may be integral with it. Conventional arrowheads have historically had two basic types of pointed arrowhead tips: bone-crushing chisel-type tips such as the hollow ground trocar tip, and razor-blade-type tips.
A trocar tip is a pointed, three sided tip used used to cut or pierce. The three sides of trocar tips are generally hollow ground. The term hollow ground refers to the grinding process used to fabricate the sides of the tip and generally means that the sides are dished-out or substantially concave, as compared to being flat. The hollow ground feature gives the tip better defined cutting edges at the juncture of the sides with each other than the cutting edges at side junctures of tips having flat sides. The hollow ground feature also gives the tip the ability to easily push the substance being penetrated away from the tip. The earliest known use of trocar tips date back to the medieval times where they were used on the leading ends of knights' lances.
The following U.S. patents are examples of broadheads having bone-crushing chisel-type tips: U.S. Pat. No. 4,676,512 issued Jun. 30, 1987 to Miroslav A. Simo titled ARROWHEAD; U.S. Pat. No. 5,145,186 issued Sep. 8, 1992 to Richard Maleski titled BROADHEAD FOR AN ARROW AND METHOD FOR SECUREMENT; U.S. Pat. No. 5,192,081 issued Mar. 9, 1993 to Gary L. Cooper titled MULTI-BLADE ARROWHEAD; U.S. Pat. No. 5,354,068 issued Oct. 11, 1994 to Richard Maleski titled BROADHEAD FOR AN ARROW AND METHOD OF SECUREMENT; U.S. Pat. No. 5,494,298 issued Feb. 27, 1996 to Richard Maleski; U.S. Pat. No. D385,327 issued Oct. 21, 1997 to Nicholas J. Delmonte titled CUTTING FERRULE BROADHEAD; U.S. Pat. No. 5,871,410 issued Feb. 16, 1999 to Miroslav A. Simo, et al. titled FERRULE WITH IRREGULAR SKIN SURFACE FOR AN ARCHERY BROADHEAD; U.S. Pat. No. 6,077,180 issued Jun. 20, 2000 to Charles C. Adams, Jr. titled ARCHERY BROADHEAD; and U.S. Pat. No. 6,626,776 issued Sep. 30, 2003 to Bruce Barrie, et al. titled EXPANDABLE BROADHEAD WITH MULTIPLE SLIDING BLADES.
The razor blade tips are generally just an extension of the cutting blades of the arrowhead and terminate in a leading pointed apex. The following U.S. patents are examples of razor-blade-type broadhead tips: U.S. Pat. No. D236,465 issued Aug. 26, 1975 to Wilton Hamilton titled METAL ARROWHEAD; U.S. Pat. No. 4,928,969 issued May 29, 1990 to Wesley S. Nagatori titled ARROWHEAD; U.S. Pat. No. 5,165,697 issued Nov. 24, 1992 to Stanley E. Lauriski et al. titled BROADHEAD ARCHERY HUNTING POINT; U.S. Pat. No. D326,889 issued Jun. 9, 1992 to Larry W. Garoutte titled ARROW BROADHEAD; and U.S. Pat. No. 5,137,282 issued Aug. 11, 1992 to Donald E. Segar, et al. titled PLASTIC MOLDED ARROWHEAD AND METHOD.
Both bone-crushing chisel-type and razor-blade-type arrowhead tips are designed to maximize penetration and therefore provide a more lethal arrowhead by cutting a larger volume of animal tissue. Despite their designs and intent both the bone crushing chisel tips and the razor blade tips fall short of providing optimum penetrating performance. Since the arrowhead razor blade type tips generally have a true cutting edge, or a cutting edge that has a small enough angle between opposing sides so as to make it as sharp as a razor or scalpel blade, they penetrate the best through soft tissues such as skin, muscles, lungs and other internal organs by slicing or cutting. But when a razor blade tip impacts bone the thin cutting blade generally gets sheared or broken-off due to the heavy impact forces delivered to it, and thus leaves a blunt snagging leading end that greatly inhibits penetration and therefore is less lethal in many instances—since arrowheads very commonly impact bone when penetrating game animals. The bone-crushing chisel tips on the other hand split right through heavy bone but lack a truly sharp cutting edge and therefore do not perform as well in penetrating the skin and other soft tissues.
Attempts in the prior art have been made to combine a scalpel sharp cutting edge with bone splitting capabilities into an optimally penetrating arrowhead tip, but these attempts have their own problems as well. For example the introduction of chisel tips with hollow ground sides, such as the three sided trocar tip for arrowhead points helped reduce the angle of the cutting edge between the sides of the tip. But the edges of conventional trocar arrowhead tips and other hollow ground arrowhead tips are still relatively dull and are a far cry from having the fine cutting angle or edge a scalpel or razor blade possesses. Other attempts in the prior art to increase the sharpness of the edges of chisel type arrowhead tips have been made by increasing the curvature of the hollow ground sides. This practice greatly weakens the tip giving it problems similar to those of the razor blade type tips and also provides a tip that does not push the tissue away from the arrowhead optimally.
U.S. Pat. No. 6,306,053 to Victor Jay Liechty, II titled RAZOR-EDGED CUTTING TIP, discloses a broadhead having having a tip body with at least one slot for engageable mounting of a cutting tip blade therein. The tip blades provide a razor sharp cutting edge situated near a forward leading end of the corresponding arrowhead. The razor sharp cutting edges of the tip blades in conjunction with the corresponding tip bodies provide cutting tips with sufficient structural integrity to both penetrate soft tissue with ease and crush or split heavy bone.